MESSRS. ALLEN AND PEPYS ON THE RESPIRATION OF BIRDS. 281 



Tlie capacity of the glass vessel was 94 cubic inches. 



Connecting tubes, &c 5 



99 

 Bulk of bird 28 



Atmospheric air 71 



Thus it appears that 71 cubic inches of atmospheric air were contained in the 

 glass vessel with the pigeon, and during 22 minutes 75 cubic inches of oxygen 

 gas were passed through this vessel at intervals of about 7 minutes, the quan- 

 tity pushed off being noticed by the register of the second gasometer. 



In about ten minutes the bird began to pant and became uneasy ; during 

 the next 2 1 minutes 72 cubic inches more of oxygen gas were passed : the bird 

 continued to pant, and the soft parts about his beak became of a bright red. 



In the next 23 minutes 89 cubic inches more of oxygen were passed, and the 

 bird was left 6 minutes longer in the 71 cubic inches contained with him in 

 the intermediate glass vessel, making the whole time one hour and twelve 

 minutes ; the bird on being released appeared very well, and did not seem at 

 all injured by the experiment. The gas being examined by the eudiometer as 

 before, the following results were obtained : 



Vol. of 

 gas before 



theexpt. y , f Carbonic 



cub.incli. Azote. Oxygen. Time. gas after Azote. Oxygen. Acid. 



71 atmos. air consisting of 56. G9 \4.3l "^"p*' 



75 oxyg. with 2 per cent azote 1.50 73.50 22' 75 consisting of 48.22 22.96 3.82 



7i oxyg. ditto 1.44 70.56 21 71.99 23.75 43.79 4.45 



89 oxyg. ditto 1.78 87.22 23 89 10.90 70.90 7.20 



Residuum 6 71 7.24 57.96 5.80 



307 61.41 245.59 72 306.99 90.11 195.61 21.27 



Thus it appears that the volume of the gas was almost unaltered, but that 

 there had been a great disturbance in the proportions of the azote. 

 Azote in the 307 cubic inches of gas : 



Before the experiment 61.41 



Found after the experiment 90.11 



Increase of azote 28.70 



MDCCCXXIX. 2 o 



